The present invention relates to a transport container system, in particular for bulk goods, comprising a stackable transport container, preferably a crate, which may be of the collapsible or non-collapsible type. This type of crate is known and used in particular for transporting bulk goods such as fruit and vegetables. The term bulk goods as used in the context of the present invention shall denote a unit of goods to be transported which consists of discrete pieces of a minimum size between 0.5 cm and 1.0 cm.
The non-collapsible and collapsible containers of the prior art, in particular crates, for transporting fruit and vegetables are made of cardboard, wood or plastic. The special feature of collapsible transport containers is that their side walls can be moved down onto the inner bottom surface of the transport containers, which results in a volume reduction of the empty transport container. When folding the container up again, the side wall elements will be arranged perpendicular (at 90°) to the inner bottom surface and will be detachably connected to each other through various means. While the bottom surface of the transport containers is of a defined size, there are containers which have side walls of different heights, in which two or four side wall elements have the same height, to allow different transport volumes to be obtained. Furthermore, on their upper side facing away from the bottom surface, the side wall elements are provided with a profile or a means to make them stackable. In order to increase the stability of the transport containers, especially as regards their stackability, these are preferably reinforced at their corners. The maximum volumetric capacity of the prior art transport containers is defined by the size of the bottom surface and the height of the side wall elements. For a higher volumetric capacity, the transport containers must have different and higher side wall elements. This does not allow for a fast adjustment of their volumetric capacity to changing consumer demands.
The sizes of certain kinds of fruit and vegetables will vary from one harvest season to the next depending on different factors, for example during their growth period. The sizes of fruit or vegetables to be packaged are specified in EC regulations. The varying sizes of the bulk goods to be transported are thus a known problem in the transport of bulk goods such as fruit and vegetables which makes optimal filling of transport containers difficult. In order to cope with the varying demands posed by the bulk goods, the transport containers, in particular crates, are machine-produced in certain sizes which are also determined by the production line and/or by the production parameters selected. This makes it impossible to rapidly change the size—and thus the volumetric capacity—of a vast number of transport containers so as to ensure optimal filling of the containers based on the size of the bulk goods without major logistic transport problems or a time-consuming change-over of production lines and resulting high costs.
The above mentioned problem will crop up with the prior art transport containers especially when relatively easy-to-produce cardboard packaging for transporting bulk goods such as fruit and vegetables is replaced with returnable containers made of plastic or a material similarly suitable for this purpose which are friendlier to the environment but also more complex and costly in production. An ideal adjustment of the transport containers to the size of the bulk goods to be transported will prove especially complex and difficult in the case of the prior art returnable plastic containers. For maximum utilization of the means of transport, the transport containers can be stacked which allows a vast number of them to be transported in large containers, on loading areas, in goods wagons or similar means of transport. The bulk goods thus transported must not protrude above the upper edge of the transport containers since this would interfere with the stacking of the transport containers or otherwise damage the bulk goods. As a consequence, the volumetric capacity of the prior art transport containers cannot be fully utilized in many instances.
The applicant's returnable transport containers, the technical term for which is “round trip containers”, come in at least ten different designs which differ in the height of their side wall elements. The heights of the side wall elements range between 8 cm and 28 cm, with heights of 8 cm, 10 cm, 13 cm, 15 cm, 16 cm, 18 cm, 20 cm and 23 cm being preferably used. The bases of these transport containers are preferably rectangular in shape and their external measurements are preferably 600 mm×400 mm. This is approximately an integer fraction of the size of the surface area of standard Euro and U.S. pallets. However, transport containers of a different size, for example 400 mm×300 mm, are also used.
NL 93 00 986 discloses a container having at least one bottom element and one wall element. Provided on the wall element are projections which can be made to engage in recesses provided in the bottom element to connect the wall element to the bottom element. It is furthermore disclosed in NL 93 00 986 how a circumferential one-piece frame may be placed on a container to enlarge its volume which is delimited by the wall element and the bottom element.
DE 103 26 574 A1 discloses a transport container, in particular for transporting bulk goods such as fruit and vegetables, comprising a collapsible or non-collapsible stackable crate having a bottom element as well as four side wall elements of a pressure- and/or load-resistant structure. For increasing the volumetric capacity of the transport container, an attachment unit is provided whose shape corresponds to that of the side wall elements and which can be placed on top of the side wall elements of the crate. The attachment unit has been designed to form a closed frame which can be folded at its diagonal corners. The foldable attachment unit is preferably made of cardboard and will be disposed of after use. The side wall elements of the crate and the side wall elements of the attachment unit can be snapped into mutual engagement when the attachment unit is put on top of the crate, and can be released again when the attachment unit is taken off.
US 2004/0222222 A1 discloses a collapsible transport container which is adjustable in height. The transport container has a base which also constitutes the bottom surface of the transport container. The transport container furthermore includes a pair of long side walls extending opposite each other and a pair of short side walls extending opposite each other, with extension walls being provided on each of the side walls. Together with the extension walls, the short and the long side walls can be folded down onto the base to reduce the volume of the empty transport container to a minimum. The short side walls and the long side walls can be arranged so as to extend perpendicular to the bottom surface in which position they will then be locked with each other by means of locking elements provided on the short side walls. If required, long extension walls may be folded out from the long side walls and short extension walls may be folded out from the short side walls so as to form—in a first embodiment—upwards extensions each of the long and of the short side walls. Once folded out, the extension walls will be mutually locked, by means of additional locking elements disposed in the short extension walls, so as to form a frame.
The attachment unit can thus be taken off and disposed at the place of delivery. Once it has been emptied and cleaned, the reusable crate may for example be folded and stacked and will then be ready for future use for which no attachment units, attachment units of a different height or the same attachment units but a different amount thereof may be required. In most cases, it therefore makes more sense to store the crates separately from the attachment units. This leads to various costs, on the one hand for producing the attachment units and on the other hand for storing crates and attachment units separately, with the increased expenditure being incurred both at the place where the crates are filled and at the place where they are made. Additional costs will also be incurred at the place where the crates with the attachment units are emptied, due to the disposal of the cardboard attachment units.